Chemistry A-Level
broad O–H shapes
What broad O–H shapes means in Chemistry A-Level, as defined for AQA.
Definition of broad O–H shapes
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Reference: AQA
A broad absorption between about 2500 and 3000 cm⁻¹ alongside the C=O means a carboxylic acid, while between about 3230 and 3550 cm⁻¹ with no C=O means an alcohol.
Topics that use broad O–H shapes
- Infrared spectroscopy (AQA A-Level)
Related terms
- absence as evidence
- below 1500 cm⁻¹
- bond vibration
- C=O near 1700 cm⁻¹
- characteristic wavenumbers
- comparison with a database
- fingerprint region
- units of cm⁻¹
Using broad O–H shapes in the exam
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